Targeting eIF5A Hypusination Prevents Anoxic Cell Death Through Mitochondrial Silencing and Improves Kidney Transplant Outcome

J Am Soc Nephrol. 2017 Mar;28(3):811-822. doi: 10.1681/ASN.2016010012. Epub 2016 Sep 9.

Abstract

The eukaryotic initiation factor 5A (eIF5A), which is highly conserved throughout evolution, has the unique characteristic of post-translational activation through hypusination. This modification is catalyzed by two enzymatic steps involving deoxyhypusine synthase (DHPS) and deoxyhypusine hydroxylase (DOHH). Notably, eIF5A may be involved in regulating the lifespan of Drosophila during long-term hypoxia. Therefore, we investigated the possibility of a link between eIF5A hypusination and cellular resistance to hypoxia/anoxia. Pharmacologic targeting of DHPS by N1-guanyl-1,7-diaminoheptane (GC7) or RNA interference-mediated inhibition of DHPS or DOHH induced tolerance to anoxia in immortalized mouse renal proximal cells. Furthermore, GC7 treatment of cells reversibly induced a metabolic shift toward glycolysis as well as mitochondrial remodeling and led to downregulated expression and activity of respiratory chain complexes, features characteristic of mitochondrial silencing. GC7 treatment also attenuated anoxia-induced generation of reactive oxygen species in these cells and in normoxic conditions, decreased the mitochondrial oxygen consumption rate of cultured cells and mice. In rats, intraperitoneal injection of GC7 substantially reduced renal levels of hypusinated eIF5A and protected against ischemia-reperfusion-induced renal injury. Finally, in the preclinical pig kidney transplant model, intravenous injection of GC7 before kidney removal significantly improved graft function recovery and late graft function and reduced interstitial fibrosis after transplant. This unconventional signaling pathway offers an innovative therapeutic target for treating hypoxic-ischemic human diseases and organ transplantation.

Keywords: cell survival; hypoxia; ischemia; kidney transplantation; renal cell biology; transplant outcomes.

MeSH terms

  • Animals
  • Cell Death / drug effects*
  • Cell Hypoxia / drug effects
  • Cells, Cultured
  • Female
  • Kidney Transplantation*
  • Lysine / analogs & derivatives*
  • Lysine / pharmacology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mitochondria / drug effects*
  • Mitochondria / physiology*
  • Mixed Function Oxygenases
  • Peptide Initiation Factors / drug effects*
  • RNA-Binding Proteins / drug effects*
  • Rats
  • Rats, Wistar
  • Swine
  • Treatment Outcome

Substances

  • Peptide Initiation Factors
  • RNA-Binding Proteins
  • eukaryotic translation initiation factor 5A
  • hypusine
  • Mixed Function Oxygenases
  • deoxyhypusine hydroxylase
  • Lysine